1. Field of the Art
The disclosure relates generally to communication systems, and more specifically, to timing recovery in an optical receiver.
2. Description of the Related Art
The most recent generation of high-speed optical transport network systems has widely adopted receiver technologies with electronic dispersion compensation (EDC). In coherent as well as in intensity modulation direct detection (IM-DD) receivers, EDC mitigates fiber impairments such as chromatic dispersion (CD) and polarization mode dispersion (PMD).
Timing recovery (TR) in the presence of differential group delay (DGD) has been identified as one of the most critical challenges for intradyne coherent receivers. In particular, it has been shown that timing information can be completely lost in optical channels with half-baud (or half-symbol period) DGD. This can result in the receiver failing to recover data received over the fiber channel, thereby decreasing performance of the optical network system.